Hot air furnace



July 24, 1934. T. R. BRIEN 9 v HOT AIR FURNACE Filed OCT.. 7, 1932 2 Sheets-Sheet l July 24, 1934. T R. BRIEN f 1,967,495

HOT AIR FURNACE Filed oct. 7, 1932 2 sheets-sheet 2 ATTQRNEYS Patented `Iuly 24, 1934 Y Y Y UNi'rso STATES PATENT LoFFicgEl HOT AIR FURNACE Theodore R. Brien, Cherry Valley, N. Y. Application October 7, 1932, Serial No. 636,715

2 Claims. (Cl. 126-99) With the ordinary vertical furnace there is a of the adjacent section, suitable incombustible comparatively short travel for the hot gases with packing material, such as rope asbestos 17, bethe result that the furnace has to be operated lng interposed between the two to'form a` tight at a high temperature and the gases enter the joint. l5 chimney at a relatively high temperature which, In the embodiment illustrated, I have shown of course, means inefficient operation. an oil burner 18 through which oil with a suit- InV the hot air furnace embodying lmy invenable amount of combustible air is vintroduced into tion there is a comparatively long fire travel and the lower portion of the combustion chamber 14. a sulcient -amount of heat is transferred from it is to be understood, however, that my invention 410 the flues to the air so that the waste gases leave is not limited to-the use of uid fuel as the burn- 5 the furnace at a relatively low temperature and ing of gas, coal, powdered fuel or any other kind the furnace may also be operated at a correof fuel ordinarily used in heating apparatus is spondingly low temperature. contemplated. In case solid fuel is to be used, My invention will best be understood by referthenl a grate would be interposed between the 1'5 ence to the accompanying drawings in which I sections 151 and 152 and the fuel would be introhave illustrated a preferred embodiment thereof duced through a front door 19 communicating and in which .y with the upper portion of the combustion cham- Fig. 1 is a front elevation, partially broken ber. away, of a furnace embodying my invention; The upper section 154 enclosing the combus- .20 Fig. 2 is a section taken along ,the line 2-2 tion chamber is provided with a passage 20 with 75 of Fig. l; which communicates an outlet iiue 21 which is Fig. 3 is a perspective view ofthe flues; providedV with three passages, the middle one of Fig. 4 is a fragmentary plan view of the which, 211, communicates with a stack 22 and is branched outlet flue leading from the combusprovided with a damper 38 voperated by a handle 25 tion chamber; 39. The other two branches'212 gradually'de- 0 Fig. 5 is an end View of Fig. 4; scend, as best shown in Fig. 3, and communicate Fig. 6 is a perspective View illustrating 'the end with flues 23 arranged in the upper portionl and of a flue section which is provided with an acat the opposite sides lof a heating chamber 24. cess opening; vThe lower ends of the branches 212 are provided '30 Fig. 7 is a longitudinal sectional view through with flanges 25. Curved pipe sections 26 pro 85 Fig. 6 and illustrating a cover plate secured in vided with flanges 27 complementary to Jche position on the end of the flue; flanges 25 are vinterposed between the ends of the Fig. 8 is a rear elevation of the cover plate; branches 212 and the main flues 23. Fig. 9 is an end elevation of the flue illus- The flues 23 on opposite sides of the heating 35 trated in Fig. 6; and chamber are preferably ofthe same construction Fig. 10 is a' sectional view illustrating a exirand ades'cription of one, therefore, will suffice 90 ble joint between twov adjacent sections of the for both. Each of nues 23 preferably comprises flue. a comparatively long section 231 which is gener- Like reference characters indicate like parts ally U-shaped in form rand joined at one end by 40 throughout the drawings. a comparatively short U-shaped section 232 to Referring to the drawings, 10 indicates the one leg of the adjacent long section. The com- 95 front wall of a furnace, 1l the rear wall and 12 plementary flanges for two sections V231 and 232 the top and side walls, the walls preferably comof the ue, which may be of the same character prising spaced plates for heat insulating puras the flanges 25 and 2'7 are illustrated in Fig. .'45 poses, a plate 13 extending across the bottom of 10, the one fiange 234 being provided with an anthe furnace. The walls forming the upper pornular recess 235 whereas the complementary tion of the furnace are preferably arch-shaped flange is provided with a bead or slightly raised as at 121, as indicated in Fig. 1. lug 236, registering with the recess 231, suitable A combustion chamber 14 is formed by walls incombustible packing material, preferably in "5d 15 which are preferably cylindrical in cross secthe form of asbestos rope 237, being located in the (165 .155 a concave recess 16 formed in the upper edge which is interposed between the raised portion tion and flared upwardly as indicated in Fig. 2. recess so that,'due to the pressure of the bead In the embodiment illustrated the walls are against the packing, a gas tight joint is proformed of sections 151, 152, 153 and 154, the vided. When the raised lug portion 236 of one lower edge of a given section interfitting with flange 234 of the flues engages the rope asbestos posite sides of the heating chamber.

and the recess 235 of the other anges, the two flanges are slightly spaced, as illustrated, when the flanges are secured together by the bolts or rivets. This provides a iiexible connection between the sections 231 and 232 as well as between the remaining sections of the iiue.

A common outlet ue 28 is provided with two branches 281 which communicate with the uppermost branches233 of the main flue 23, the other end being connected to the stack 22.

The front ends of the sections 231 are provided with access openings 29, preferably elliptical in form, as best shown in Figs. 6 and 7 and extend through openings in the front furnace Wall. The access openings may conveniently be closed by means of cover plates 31 formed with iianges 32 surrounding the ends of the section 231. The cover plates are preferably equipped with a clamping bar 33 mounted on an operating stub shaft 34 passing through an opening in the cover plate 31 and provided at its outer end with an operating handle 35. The ends of the bar 33 engage cam grooves 36 formed on the inner surface of the end of the flue 231, as best shown in Figs. 6 and 7.

'In assembling the cover plate, the bar is, of course, placed in position with the member 33 in vertical position as shown in Fig. 8. Then by turning the bar 33 it engages the cam grooves 36 and clamps the cover plate against the end of the flue section 231. Suitable packing material 37 is preferably interposed Ybetween the cover plate and the end of the flue.

VAir is admitted to the lower portion of the heating chamber 24 through an air inlet opening 40 located at the bottom of the furnace, the air passing upwardly in contact with the walls of the combustion chamber 14 and over the flues 23 to one or more air outlet openings 41 which, of course, may lead to rooms which are to be heated.

In operation the heated gases are conducted from the upper portion of the combustion chamber 14 through the passage 20. When the furnace is initially started, the damper 38 is opened thereby permitting the gases to pass to the stack direct until the gases therein are suiciently 'heated to create a draft. The damper 38 is then closed, and the heated gases gradually descend from theoutlet flue 21 through the branches 212 and the sections 26 to the flues 23 located on op The gases then gradually ascend through the sections 231 and 232 and through the upper legs 233 to the youtlet nue 28 through which they pass to the stack.

By providing branched nues on opposite sides of the heating chamber in the marmer described and causing the gases to ascend in the major portion of the flues, I have provided a comparatively long travel for the hot gases and thereby obtained a high heat transfer from the hot gases to the air while providing a strong draft for the furnace.

The provision of the spaced anges with interposed packing material is particularly important where there is a considerable drop in the temperature of the gases as in the described construction which would cause differences in expansion and contraction between different portions of the flue. Such differences are readily compensated for by the yielding packing.

The flues may readily be cleaned through the cleaning openings 29 of the sections 231 of the iiue by removing the cover plates 31.

While I have described my invention in its preferred embodiments it is to be understood that the Words which I have used are words of description rather than of limitation and that changes within the purview of the appended claims may be made without departing from the true scope and spirit of my invention in its broader aspects.

What I claim is:

1. In a hot air furnace, means defining a combustion chamber, means defining a heating chamber surrounding the combustion chamber, an outlet ue extending from the top of the combustion chamber to the rear of the heating chamber, and heating flues extending from opposite sides of the outlet flue and each having sections extending outwardly and downwardly and having parallel sections alternately connected at opposite ends and joined to a common outlet at the top of the heating chamber at the'highest point of the flues and forming an arch over the sides and top of the combustion chamber, whereby the gases pass from the combustion chamber downwardly and outwardly and then upwardly around the sides of the combustion chamber and then inwardly toward the center and over the top of the combustion chambenall of said flue branch connections having a gradually curvedcontour.

2. In a hot air furnace, means dening a combustion chamber, means defining an arch shaped air heating chamber surrounding the combustion chamber and having parallel front and back walls, heating flues in the form of an arch corresponding with the contour of the air chamber and positioned on opposite sides of the combustion chamber comprising long U-shaped sections having oval apertures at the closed end extending through the front wall, curved and downwardly extending sections joining the lower ends of the nues with the top of the combustion chamber, short U-shaped sections joining adjacent ends of the Ylong U-shaped sections and a Y-shaped section joining the upper ends of the ues and forming a common outlet whereby the gases from the combustion chamber are first di rected downwardly and outwardly and then upwardly and inwardly and are discharged at the highest point of the flue, all of said sections being detachably joined, and covers for closing the oval apertures of the closed end of the long U- shaped sectionsextending through the front wall.

THEODORE R. BRIEN. 

